What is the variable that is manipulated by the experimenter during an experiment called

Independent variable
The independent variable is the variable that is controlled and manipulated by the experimenter. For example, in an experiment on the impact of sleep deprivation on test performance, sleep deprivation would be the independent variable.

Answer:

the word that best describes martin luther king jr.'s tone in the video is dignified

explanation:

martin luther king, jr. was a social activist and baptist minister who played a key role in the american civil rights movement from the mid-1950s until his assassination in 1968. the video shows his manner and attitude having or showing a composed or serious manner that is worthy of respect so dignified is the correct answer

Molybdeum(mo)orruthenium (ru)actually, elements with similar chemical properties as technetium would bemn, re, and bh. this is because elements in the same group/family (column) have similar chemical properties. elements in the same period (row) have the same number of energy levels (or shells).